Lab technician mixes ingredients added to batch.

By David Safenovitz and Sebastien Lebon

Engineers find an innovative solution involving low-melt labels to guarantee the right mix when developing rubber products for automotive market.

Editor’s Note: “Anyone who has ever put an incorrect bag of ingredients into a mixer knows the importance of proper labeling.” So says Sebastien Lebon, the mixing process engineer at Paulstra, a manufacturer of rubber products. Lebon is making sure mistakes caused by improper labeling never happen at his plant. In the following article, he shares how he and David Safenovitz, vice president of Paragon Data Systems, worked together to guarantee batch integrity at Paulstra’s Grand Rapids plant. Paragon specializes in automatic data collection systems including printers, scanners and labels.

The process of making rubber is more complex than one might think. It requires a wide range of high-performance compounds that must meet stringent requirements to ensure the integrity of finished products such as tires, hoses, belts, seals and molded goods.

Many customers request custom compounds be used to meet proprietary recipes, and it is not uncommon for a rubber fabricator to mix hundreds of different ingredients in one day. The more compounds required, the more ingredients used. The more ingredients used, the more challenging it is to ensure that every batch contains the right components, as specified, in the right proportions.

In order to make a profit while still ensuring the highest quality product, manufacturers look for new solutions that will increase production output and decrease overhead costs. One way for rubber manufacturers to capture more market share and increase customer satisfaction is to perfect their method of mixing rubber components. By doing this, they can ensure rubber batch integrity and offer the highest level of quality and consistency.

Bags with unsatisfactory labeling methods click to enlarge

Paulstra, a manufacturer of rubber products that provide shock, noise and vibration control as well as vibration management for automotive applications, improved its rubber batch integrity with the use of a new labeling solution. The company has two manufacturing plants in Michigan, which are quality certified and incorporate lean manufacturing techniques with in-process verification systems. The plants contain dedicated stations for metal preparation, adhesive coating, injection transfer and compression molding and robotic assembly. The company’s rubber mixing facility is in Grand Rapids. Because it produces thousands of rubber products each day, the rubber mixing line is one of the most crucial stages at the plant. Engineers deal with hundreds of rubber mixing batches every day with nearly 100 separate chemicals in powder and pellet form, including curatives and additives such as antioxidants.

The company wanted to improve the efficiency of its rubber mixing processes. Specifically, it wanted to reduce waste and increase batch integrity in the rubber batch inclusion bag labeling area. The main challenge was batch labeling. Improperly labeled bags can lead to lack of product confidence because there is no way to retrace steps and verify contents once ingredients are added to the mix. The need to label each bag is as crucial, if not more, as ensuring that each batch contains the right mix.

In order to improve processes, Paulstra examined different labeling methods to find the most efficient way to identify bags. Initially, bags were labeled using marker pens, but the ink sometimes smeared. The company experimented with printed tags using a thermal printer, but tags couldn’t be adhered to bags without paper material contaminating the product. Various methods of temporarily attaching tags were tried, but when tags separate from bags, there is no way to verify that correct recipes are used. This endangers quality assurance and makes efforts to establish traceability time-consuming.

Bag with Lomel label click to enlarge

In the search for a better labeling method, Paulstra approached J. Drasner, the manufacturers of the Lomel bag, and asked about its system. J. Drasner recommended a labeling solution by Paragon Data Systems that uses low-melt labels made from the same 160 EVA film as the J. Drasner Lomel batch-inclusion bag, which allows the label to completely disperse, along with the bag, when added to the mix. The system prints labels on demand with all relevant information in plain text and bar-code form. An important feature of the labeling system is its intelligibility. At the mixing station, the system tells the operator which compounds, and in which amounts, are specified for each mix. It also verifies each ingredient and provides a record to ensure traceability. The solution relies on a Zebra 105SL industrial printer, which is designed to produce crisp, clear text and graphics on labels. It also uses an Intermec Saber 1552C scanner to collect bar-code data and perform ingredient validation. A PC network is in place with PC stations at each workstation.

The labeling system from Paragon Data Systems has been in operation at Paulstra’s mixing facility for about two years. The new system has reduced machine downtime significantly and has increased productivity by reducing the time spent correcting errors. Most important, the process has guaranteed the integrity of each batch, which is crucial since Paulstra’s customers are automobile manufacturers who require lot and batch traceability.

Additional information is available by contacting Paragon Data Systems Inc., 2218 Superior Ave., Cleveland, OH 44114, at 800-211-0768 or infoparagondsi.com or by visiting www.paragondsi.com.